Many files stored in computer systems contain data that is not expected to change over time. In some systems, the percentage of files that are expected to remain unchanged can range up to 90% of all of the stored files. Examples of data and files that are expected to remain unchanged include medical images, images of cancelled bank checks, images collected by oil and gas exploration, surveillance videos, files containing television news clips, and many types of archival and historical data. Other files are expected to change regularly, such as a database file, a word processing document that is being edited, and any type of file that represents current state, such as a file holding cumulative email messages as they arrive.
Stored files must be accessible. Further, they must be accessible whether it's the kind of data that changes quickly, such as a file storing current email, or whether it is the kind of data that will not change much over time, such as medical images. CAS technology can be used to store different types of data including, by way of example, data that does not change over time. Generally, a “handle” (not necessarily the location of the file in a directory) or a GUID (globally unique identifier) is created for each stored object. This handle can be created based on known techniques, such as hashing.
Current storage systems have a number of issues. The options for production of groupings of files may be limited. Another issue with current systems is that the heterogeneous storage of data (e.g., but a number of different medical imagers and reporting systems), can make accessing stored data difficult—both because of the distributed nature of the storage and because of the heterogeneous nature of the storage of the data.
These and other issues are addressed by the embodiments described herein. Some embodiments address one or more of these issues, while others address a different subset of issues.